LASER GLASS HOST COMPOSITIONS COMPRISING TeO{11 AND BaO

ABSTRACT

Laser glass host compositions for effective lasing amounts of Nd2O3 are disclosed, the laser glass compositions comprising TeO2 and BaO, the compositions generally being: 1. ABOUT 77-90 MOLE PERCENT TeO2 and about 10-23 mole percent BaO; and 2. ABOUT 67-73 MOLE PERCENT TeO2 and about 27-33 mole percent BaO. Also disclosed are methods of making highly effective laser articles, such as rods and discs, and the new use of the abovedescribed TeO2/BaO glass compositions for forming laser articles, the new use including forming laser articles from the glass compositions, pumping the resultant laser articles to provide an energy inversion, and lasing the pumped article.

[451 Sept. 17, 1974 LASER GLASS HOST COMPOSITIONS COMPRISING TeO AND BaO[75] Inventor: Richard F. Cooley, Toledo, Ohio [73] Assignee:Owens-Illinois, Inc., Toledo, Ohio [22] Filed: June 27, 1973 [21] Appl.No.: 374,107

[52] US. Cl. 33l/94.5, 252/301.4

[51] Int. Cl. H018 3/16 [58] Field of Search 331/945; 252/301.4, 301.6;106/47 [56] References Cited UNITED STATES PATENTS 3,462,707 8/1969Pearson et al. 331/945 Primary Examiner-William L. Sikes Attorney,Agent, or Firm-Richard D. Heberling; E. J. Holler [5 7] ABSTRACT Laserglass host compositions for effective lasing amounts of Nd O aredisclosed, the laser glass compositions comprising TeO and BaO, thecompositions generally being:

1. about 77-90 mole percent TeO and about 10-23 mole percent 8210; and2. about 67-73 mole percent TeO and about 27-33 mole percent 8210.

Also disclosed are methods of making highly effective laser articles,such as rods and discs, and the new use of the above-described TeOJBaOglass compositions for forming laser articles, the new use includingforming laser articles from the glass compositions, pumping theresultant laser articles to provide an energy inversion, and lasing thepumped article.

15 Claims, No Drawings LASER GLASS HOST COMPOSITIONS rSI G, T 02 ND 1 9INVENTION The present invention relates to laser glass host compositionsfor effective lasing amounts of Nd:();,, the host compositionscomprising TeO and BaO in certain molar amounts. The present inventionalso relates to methods of making laser articles, such as rods, withincreased efficiency, the methods including the steps of:

l. forming laser articles from glass articles comprising certain amountsof TeO and BaO, the glass being host for an effective lasing amount ofNd O 2. pumping the laser article to provide an energy inversion; and

3. lasing the pumped article.

The present invention also relates to a method for making anoutstanding, highly efficient glass laser article by melting laser glassbatch-forming materials to provide a molten glass comprising certainamounts of Te and BaO, the molten glass, when solidified, being capableof functioning as a host for an effective lasing amount of M 0 forming aglass blank from the molten glass; and fabricating the outstanding laserarticles from the blank.

It is desirable to provide laser glass compositions that can be used tomake outstanding, highly efficient glass laser articles. It is alsodesirable to provide a new use for glass compositions comprising TeO andBaO in which the new use includes the steps of:

l. forming a glass laser article from the abovedescribed glasscomposition that is a host for an effective amount of Nd,o,;

2. pumping the laser article; and

3. lasing the pumped article.

It is an object of the present invention to provide a laser glasscomposition containing TeO and BaO, the molar amounts thereof beingdefined by the following compositional ranges:

I. about 77-90 mole percent TeO and about 10-23 mole percent BaO; or

2. about 67-73 mole percent TeO and about 27-33 mole percent 8210, theglass composition also being a host for an effective lasing amount ofNdgoa- It is an object of the present invention to provide a method formaking a glass article, such as a glass laser rod, disc or the like, themethod comprising the steps of:

l. melting laser glass batch-forming materials to provide molten glasscomprising TeO- and BaO in certain molar proportions, namely:

a. about 77-90 mole percent TeO and about 10-23 mole percent BaO; or

b. about 67-73 mole percent TeO and 27-33 mole percent BaO, the moltenglass, when solidified, being a host for an effective lasing amount ofNdgoa;

2. forming a glass laser blank from the molten glass; and

3. fabricating a laser article from the blank to provide a veryefficient laser article.

It is an object of the present invention to provide the new use for aglass composition as a glass laser article in which the glass comprisesTeO and BaO in certain molar proportions; namely:

the steps of:

1. forming a glass laser article from the glass composition comprisingTeO and BaO, along with the effective lasing amount of Nd O 2. pumpingthe laser article to provide an energy inversion; and

3. passing monochromatic light through the pumped article to cause astimulated emission at about 1.06 microns.

lt is an object of the present invention to provide an outstanding,highly efficient glass laser article, including a rod or disc, made froma glass composition comprising TeO and BaO in certain molar amounts andcontaining an effective lasing amount of Nd o These and other objectswill become apparent from the specification that follows and theappended claims.

The present invention provides excellent laser glass host compositionsfor effective lasing amounts of Nd O the host compositions comprisingTeO and BaO, the compositions having certain molar proportions accordingto the following two compositions:

1. about 77-90 mole percent Te0 and about 10-23 mole percent BaO; and

2. about 67-73 mole percent TeO and about 27-33 mole percent BaO, theglass being a host for an effective lasing amount of Nd O Preferably,the molar amounts of Te0 and BaO are set forth in the following twocompositions:

1. about 82-85 mole percent TeO and about 15-18 mole percent BaO; and

2. about 69-71 mole percent TeO and about 29-31 mole percent BaO, thesecompositions containing an effective lasing amount of Nd O which ispreferably about 0.01-1.5 mole percent.

The present invention also provides methods for making highly efficientglass laser articles, the methods including the steps of:

l. melting laser glass batch-forming materials to provide a molten glasscomprising TeO and 8210 in certain molar proportions as set forth in thefollowing two compositions:

a. about 77-90 mole percent TeO, and l0-23 mole percent BaO; and

b. about 67-73 mole percent TeO and about 27-33 mole percent BaO, theglass being an effective host for an effective lasing amount of Nd,o,;

2. forming a glass laser blank from the molten glass; and

3. fabricating outstanding laser articles from the laser blank.

The present invention provides the new use for a glass composition as aglass article in which the glass comprises TeO and BaO in one of the twocompositions as follows:

1. about 77-90 mole percent TeO and 10-23 mole percent BaO; or

2. about 67-73 mole percent TeO and about 27-33 mole percent BaO, theglass being a host for an effective lasing amount of Nd O the new usecomprising the steps of:

l. forming a glass laser article from the glass compositions comprisingTeO and BaO with an effective lasing amount of M1 2. pumping the laserarticle to provide an energy inversion; and

3. lasing the pumped laser article.

A zinc tellurite glass consisting essentially of a major molarproportion of TeO and between about 20 and 40 molar percent of ZnO isdescribed and claimed in Redman, U.S. Pat. No. 3,423,326. These zinctellurite glasses were reported as having some fluorescent activity whendoped with Nd O As previously indicated, the outstanding laser glasshost compositions of the present invention surprisingly exhibit muchhigher fluorescent activity than the zinc tellurite glasses of U.S. Pat.No. 3,423,326, the increased fluorescent activity indicating a greaterlasing efficiency for laser articles made from the host compositions ofthe present invention. As previously described, only certain molarproportions of TeO ZrO and ZnO can be used to provide the highlyefficient laser articles, such as rods and discs. The increase influorescent activity is generally at least about 50% and preferably atleast about 60 or 70%, the increase often being as much as 100% or more.

In the previously mentioned Redman U.S. Pat. No. 3,423,326, there is nomention of any glass system glass rod, as set forth, for instance, inU.S. Pat. No. 3,471,409, to Lee and Rapp, the composition comprising theingredients that follow in approximate mole percentages:

Ingredient Mole Percent 510 60 A1 0: 2.5 27.5 C210 10 Nd,0 0.5

EXAMPLE 1 PART A A 15 gram melt was prepared by mixing reagent grade rawmaterials, in the following molar percent and also for convenience,weight percent, with ml. of W k.

other than that of a glass host composition consisting essentially oftellurium oxide and zinc oxide. There is no suggestion in the previouslymentioned Redman patent that highly efficient laser articles can be madefrom a host composition containing certain molar amounts of TeO and BaO.

The outstanding laser glass host compositions of the present invention,as previously indicated, contain TeO and BaO, in general ranges,according to the following two compositions:

1. about 77-90 mole percent TeO and about 10-23 mole percent 8210; and

2. about 67-73 mole percent Te0 and about 27-33 mole percent BaO, theglass being a host for an effective lasing amount of Nd O which isgenerally about 0.01-1 .5 mole percent and is preferably about 0.5-1.2mole percent.

Excellent glass laser host compositions are those, for instance, inwhich the glass comprises about 77 mole percent TeO and 23 mole percentBaO; or about 83 mole percent TeO and 17 mole percent BaO; or 80 molepercent'l'eg and 20 mole percent BaO.

An increased lasing efficiency is obtained for glass laser rods anddiscs in accordance with the present invention. The increase influorescent activity unexpectedly is at least about 50% over that of azinc tellurite glass containing 65 mole percent TeO and mole percentZnO. The increase in fluorescent activity of the glasses of the presentinvention is surprisingly at least about 50% over that of alithia-calcia-alumino silicate The slurry was mixed for 10 minutes andpoured into a gold crucible. The crucible was placed in an aircirculating oven with the temperature maintained at 1 10 C. overnight toremove the water. The crucible was then placed in an electric resistancefurnace with the temperature at 750 C. for 3 hours, or until homogenous,after which the molten glass immediately poured into a preheated (260C.) graphite mold forming a disc having an 11/16 inch diameter and M1inch thickness. The graphite mold was placed in an annealing ovenmaintained at 340C. After 1 hour, at 340 C., the temperature of theannealing oven was lowered at a rate of 38 C. per hour to 250 C. afterwhich the annealing oven was turned off and the mold cooled to roomtemperature.

The solid, annealed glass disc was removed from the mold, wet ground andpolished with close tolerance to a thickness of 0.195 inches and adiameter of 0.687 inches. The refractive index of the finished polishedglass disc was measured to be 2.13.

PART B The polished glass disc from Part A was tested for fluorescenceintensity and decay time in a high power pulsed test system. The discwas placed in a holder and exposed to a beam oflight from an EC and Gmodel FX 12-25 xenon flash lamp. The flash lamp had a flash duration ofabout 20 microseconds. The disc was not observed to solarize afterrepeated excitation by the flash lamp. The fluorescence intensity anddecay time of the excited sample was measured by photographing theoscilloscope display of the 1,060 nonometer fluorescent intensity versustimeon a Tektronix Model 556, Dual Trace oscilloscope connected to anRCA S-l photomultiplier, having a narrow band pass filter.

PART? The fluorescence intensity measurement was normalized againstED-2, a glass laser composition of Owenslllinois, lnc., comprising, inmole percent, 60.0% SiO The polished glass disc from Part A was testedfor flu- 2 5% A1 275% LL 0, 10% C 0, 0.16% C 0 a d orescence intensityand decay time as described in Part 05% Nd o di l d i U5, P N 3,471 409,as B of Example 1. The normalized fluorescence intensity Example 1. Thefluorescence intensity was found to be was and the Correctedfluorescence intensity was 2.87 when normalized against the glass lasercomposi- The fluorescence decay time was 174 mieresee tion; 2.87 timesthe intensity of the glass laser composi- 2 9 tron.

The fluorescence intensitywas corrected for the re- EXAMPLE 4 fractiveindlces of the glass disc and the reference glass laser composition by APA T 3. Fl (Corrected) Fl f i 7 A 15 gram melt was prepared and polishedglass discs disc) 1 prepared therefrom as described in Part A of ExampleThe corrected fluorescence intensity was 1.54. The flu- 1, except themolar or weight percentages of the raw orescence decay time was 170microseconds. 1131311818 were as follows; A 7 Ingredients Mole PercentWeight Percent Host Glass Laser Article Host Glass Laser Article TeO,80.0 79.4 80.4 79.4 BaO 20.0 19.8 19.6 19.1 Ndgoa 0.7 1.5

EXAMPLE 2 The refractive index of the finished polished glass PART Adisc was measured to be 2.09.

A 15 gram melt was prepared and polished glass discs prepared therefromas described in Part A of Example 1 except the molar or weightpercentages of the raw m e ls .w r asio tzws PART B The polished glassdisc from Part A was tested for fluorescence intensity and decay time asdescribed in Part 52 Exam 1- enqrm zss th szrssccms .i ty

Ingredients Mole Percent Weight Percent Host Glass Laser Article HostGlass Laser Article TeO, 90.0 89.2 90.3 88.8 13210 10.0 9.9 9.6 9.8 Nd,00.8 1.7

The refractive index of the finished polished glass disc was measured tobe 2.13.

PART B The polished glass disc from Part A was tested for fluorescenceintensity and decay time as described in Part B of Example 1. Thenormalized fluorescence intensity was 2.41 and the correctedfluorescence intensity was 1.25. The fluorescence decay time was 140microseconds.

EXAMPLE 3 PART A A 15 gram melt was prepared and polished glass discsprepared therefrom as described in Part A of Example 1, except the molaror weight percentages of the raw materials were as follows:

1. about 77-90 mole percent TeO and lO-23 mole H percent BaO; or

2. about 67-73 mole percent TeO and about 77-33 mole percent BaO can beused in place of the specific laser compositions used in the workingexamples; for example, the host glass composition of 66.7 mole percentTeQ and 33.3 mole percent 8210, set forth in Exlngredients Mole PercentWeight Percent Host Glass Laser Article Host Glass Laser Article TeO80.0 79.6 80.4 79.6 BaO 20.0 19.8 19.6 19.1 Nd,0, 0.6 1.2

' ample l. As previousiy indicated, substantially equivalent results canbe obtained when the above laser glass host composition set forth inExample 1 is substituted for by a host composition comprising 77 molepercent TeO and 23 mole percent BaO; or a host composition comprising 83mole percent TeO, and about 17 mole percent BaO.

What is claimed is:

1. A laser glass composition comprising TeO and BaO, the proportions ofTeO and BaO in molar amounts being about 77-90 mole percent TeO- andabout 10-23 mole percent BaO or about 67-73 mole percent TeO and about27-33 mole percent BaO, the glass being a host for an effective lasingamount of Nd o 2. A laser glass composition as defined in claim 1 inwhich the proportion of TeO to BaO is about 77-90 mole percent TeO andabout l-23 mole percent BaO.

3. A laser glass composition as defined in claim 1 in which theproportion of TeO to BaO is about 67-73 mole percent TeO and about 27-33mole percent BaO.

4. A laser glass composition as defined in claim 1 in which theproportions of Te0 and BaO are about 82-85 mole percent Te0 and aboutl5-l8 mole percent BaO.

5. A laser glass composition comprising about 69-71 mole percent TeOabout 29-31 mole percent BaO, and an effective lasing amount of Nd O 6.A laser glass composition as defined in claim I in which the amount ofNd O is about 0.0] to 1.5 mole percent.

ficiency over that of a lithia-calcia-silicate laser glass compositioncontaining Nd o 7. A laser glass composition as defined in claim 1 in10. In a method of making a glass laser composition in which the glasslaser has increased laser efficiency, the improvement which comprisespreparing a laser article from a glass host comprising TeO and BaO. theamounts of TeO and BaO being about 77-90 mole per- I cent TeO and about10-23 mole percent BaO or about 67-73 mole percent TeO and about 27-33mole pera cent BaO, the host containing an effective lasing amount of NdO 11. A method of making a laser glass composition having increasedlasing efficiency, the method comprising the steps of making a glasshost from a TeO-JBaO glass composition, the proportions of TeO and 3210in molar amounts being about 77-90 mole percent Te0 and about l0-23 molepercent BaO or about 67-73 mole percent TeO- and about 27-33 molepercent 8210, and an effective lasing amount of Nd O 12. The new use ofa TeO /BaO glass composition as a glass host forNd- O for a laserarticle such as a rod, disc and the like, the new use comprising:

1. forming a laser article from a glass composition comprising Te0 andBaO, the proportions of TeO, and BaO in molar amounts being about 77-90mole percent TeO and about l0-23 mole percent BaO or about 67-73 molepercent TeO and about 27-33 mole percent BaO. the glass being a host foran effective lasing amount of Nd o 2. pumping the laser article to causean energy inversion; and

3. passing monochromatic light through the article to cause stimulatedemission at a wavelength of about 13. A laser glass article made fromthe composition 15. A laser article made by the method defined inclaim"!!! 7, .7

1. ABOUT 77-90 MOLE PERCENT TEO2 AND ABOUT 10-23 MOLE PERCENT BAO; AND2. pumping the laser article to cause an energy inversion; and
 2. Alaser glass composition as Defined in claim 1 in which the proportion ofTeO2 to BaO is about 77-90 mole percent TeO2 and about 10-23 molepercent BaO.
 2. ABOUT 67-73 MOLE PERCENT TEO2 AND ABOUT 27-33 MOLEPERCENT BAO. ALSO DISCLOSED ARE METHODS OF MAKING HIGHLY EFFECTIVE LASERARTICLES, SUCH AS RODS AND DISCS, AND THE NEW USE OF THE ABOVEDESCRIBEDTEO2/BAO GLASS COMPOSITIONS FOR FORMING LASER ARTICLES, THE NEW USEINCLUDING FORMING LASER ARTICLES FROM THE GLASS COMPOSITIONS, PUMPINGTHE RESULTANT LASER ARTICLES TO PROVIDE AN ENERGY INVERSION, AND LASINGTHE PUMPED ARTICLE.
 3. passing monochromatic light through the articleto cause stimulated emission at a wavelength of about 1.06 microns.
 3. Alaser glass composition as defined in claim 1 in which the proportion ofTeO2 to BaO is about 67-73 mole percent TeO2 and about 27-33 molepercent BaO.
 4. A laser glass composition as defined in claim 1 in whichthe proportions of TeO2 and BaO are about 82-85 mole percent TeO2 andabout 15-18 mole percent BaO.
 5. A laser glass composition comprisingabout 69-71 mole percent TeO2, about 29-31 mole percent BaO, and aneffective lasing amount of Nd2O3.
 6. A laser glass composition asdefined in claim 1 in which the amount of Nd2O3 is about 0.01 to 1.5mole percent.
 7. A laser glass composition as defined in claim 1 inwhich there is 77 mole percent TeO2 and 23 mole percent BaO.
 8. A laserglass composition as defined in claim 1 in which the amount of TeO2 isabout 83 mole percent and the amount of BaO is about 17 mole percent. 9.A laser glass composition as defined in claim 1 comprising 80 molepercent TeO2 and 20 mole percent BaO, the composition exhibiting anincrease in laser efficiency over that of a lithia-calcia-silicate laserglass composition containing Nd2O3.
 10. In a method of making a glasslaser composition in which the glass laser has increased laserefficiency, the improvement which comprises preparing a laser articlefrom a glass host comprising TeO2 and BaO, the amounts of TeO2 and BaObeing about 77-90 mole percent TeO2 and about 10-23 mole percent BaO orabout 67-73 mole percent TeO2 and about 27-33 mole percent BaO, the hostcontaining an effective lasing amount of Nd2O3.
 11. A method of making alaser glass composition having increased lasing efficiency, the methodcomprising the steps of making a glass host from a TeO2/BaO glasscomposition, the proportions of TeO2 and BaO in molar amounts beingabout 77-90 mole percent TeO2 and about 10-23 mole percent BaO or about67-73 mole percent TeO2 and about 27-33 mole percent BaO, and aneffective lasing amount of Nd2O3.
 12. The new use of a TeO2/BaO glasscomposition as a glass host for Nd2O3 for a laser article such as a rod,disc and the like, the new use comprising:
 13. A laser glass articlemade from the composition defined in claim
 1. 14. An article as definedin claim 1 in the form of a rod.
 15. A laser article made by the methoddefined in claim 11.